In hospital for the past two months, Jayalalithaa started speaking last Friday, much to the relief of her supporters. Apollo Hospitals Chairman Dr Prathap C Reddy confirming the news had said that the Tamil Nadu chief minister was speaking using a valve attached to a tracheostomy tube.

Rediff.com provides a simple explainer on the machine that helped the Tamil Nadu CM speak. 

Normally, a patient that has undergone a tracheostomy (an incision in the windpipe made to relieve an obstruction to breathing) has difficulty in speaking.

In order to help those who have undergone a tracheostomy, there is a speaking valve that is used, which is an attachment that sits at the end of the tracheostomy tube and is designed to temporarily close every time you breathe out. This prevents the air from leaking out of the tube and allows one to speak. However, it can take a while to get used to speaking with the valve.

Once the speaking valve is attached, patients are referred to a speech therapist who would train one on how to speak while the tracheostomy tube is in place. 

Patients may need to build up the strength and ability to use the valve, but most children will be able to use the speaking valve all day after a period of adjustment. 

In Jayalalithaa's case, she can speak for a few minutes with the aid of the speaking valve. However, doctors say it won't be a permanent feature for the CM. 

Photograph: Babu/Reuters.